1. Field of the Invention
This invention relates to an inflator for inflating articles such as personal floatation devices, rafts, buoys, and emergency signaling equipment. More particularly, this invention relates to inflators whose housings may be directly heat-sealed to the inflatable article while assuring that the inflatable article remains inflated even when the gas cartridge of the inflator is removed.
2. Description of the Background Art
Presently, there exist many types of inflators designed to inflate inflatable articles such as personal floatation devices (life vests, rings and horseshoes), life rafts, buoys and emergency signaling equipment. Inflators typically comprise a body for receiving the neck of a cartridge of compressed gas such as carbon dioxide. A reciprocating pierce pin is disposed within the body of the inflator for piercing frangible seal of the cartridge to permit compressed gas therein to flow into a manifold assembly of the inflator and then into the article to be inflated. Typically, a manually movable firing lever is operatively connected to the piercing pin such that the piercing pin pierces the frangible seal of the cartridge upon jerking of a ball lanyard. U.S. Pat. No. 3,809,288, the disclosure of which is hereby incorporated by reference herein, illustrates one particular embodiment of a manual inflator.
Water-activated actuators have been incorporated into manual inflators so that in an emergency situation such as downed aviator, injured person or a man overboard, the inflator is automatically actuated to inflate the inflatable article to which it is connected. Representative automatic actuators for inflators are disclosed in U.S. Pat. Nos. 3,059,814, 3,091,782, 3,426,942, 3,579,964, 3,702,014, 3,757,371, 3,910,457, 3,997,079, 4,223,805, 4,267,944, 4,260,075, 4,382,231, 4,436,159, 4,513,248, 4,627,823, and 5,076,468, the disclosures of which are hereby incorporated by reference herein.
As disclosed in the above-referenced patents, inflators, whether manually or water-activated, are typically connected to the inflatable article by means of the manifold assembly that consists of a metal manifold having a lower flange which is molded in situ with a rubber flange to establish a flow path between the flange and the metal manifold. A one-way valve, such as a schraeder valve, is installed in the manifold. During installation, a hole is formed in the inflatable article and the manifold is positioned therethrough. The flange of the manifold assembly is then heat-sealed to the wall of the inflatable article. Notably, the one-way valve in the manifold permits inflation of the inflatable article while precluding deflation once inflated. Representative patents relating to manifold assemblies are U.S. Pat. Nos. 5,080,402, 5,058,933, 5,058,932, 4,216,182, 3,809,288 and 3,754,731, the disclosures of which are hereby incorporated by reference herein.
Correspondingly, typical inflators comprise a manifold hole which is configured and dimensioned to receive the manifold of the manifold assembly. A locking nut is threaded onto the end of the manifold to secure the inflator. An O-ring seal is provided to prevent leakage between the manifold and the inflator.
During use, upon firing of the inflator, either manually or automatically, gas from the compressed gas cartridge flows into the manifold hole of the inflator and then into the manifold. The gas then flows past the one-way valve in the manifold and into the inflatable article. Since the one-way valve of the manifold assembly precludes deflation of the inflatable article, the gas cartridge may be removed from the inflator and the inflatable article will remain inflated.
While manifold assemblies have been in extensive use in the industry for many years, they are relatively expensive to manufacture and require additional assembly operations. Accordingly, there existed a need in the inflator industry for an inflator which may be heat-sealed directly to the inflatable article thereby obviating the need for manifold assemblies and the like.
U.S. Pat. No. 4,894,036, the disclosure of which is hereby. incorporated by reference herein, discloses an inflator which may be heat-sealed directly to an inflatable article thereby obviating the need for manifold assemblies and the like. The heat-sealable inflator as shown in such patent includes a mounting flange integrally formed about the housing of the inflator. The housing together with the integral mounting flange are composed of a plastic or similar material which may be heat-sealed to inflatable articles composed of conventional plastic or other materials. The housing includes a reciprocal pierce pin and a firing lever. A pair of compression springs are provided at opposing ends of the pierce pin to exert forces thereon in opposite directions. A pair of O-rings is also provided at opposing ends of the pierce pin. During firing upon jerking of the manual firing lever, the cammed end thereof exerts a force on the rearward (stronger) spring and causes the pierce pin to move forwardly and pierce the gas cartridge. The cammed end of the manual firing lever is configured such that upon further movement of the lever, the pierce pin may be blown-back fully rearwardly by means of the forward (weaker) compression spring combined with the pressure exerted by the gas from the gas cartridge. The bore of the housing in which the pierce pin is reciprocatably positioned is configured in such a manner that when the pierce pin is blown-back fully rearwardly, the gas may flow through a port into the inflatable article. However, once the gas has escaped from the gas cartridge into the inflatable article, the lost pressure allows the rearward (stronger) spring to return the pierce pin assembly to its rest position. The bore of the housing is configured so that when the pierce pin is in its rest position, the O-rings seal the port both forwardly and rearwardly in the bore thereby precluding the gas from the inflatable article from escaping.
Unfortunately, the specific design of the heat-sealable inflator as shown in U.S. Pat. No. 4,894,036 is expensive to manufacture due to the necessity of dual springs and its other components. Moreover, it appears that the specific design could undesirably prevent inflation if the firing lever was only moved partially through its path of travel (see FIG. 5 thereof).
U.S. Pat. No. 5,564,478, the disclosure of which is hereby incorporated by reference herein discloses an improved heat sealable inflator having a design that is significantly easier to manufacture and less costly. The heat sealable inflator as disclosed in U.S. Pat. No. 5,564,478 comprises a housing with an integrally formed mounting flange that is injected molded. A pierce pin assembly is then assembled within a bore in the housing. A firing lever is then pivotally connected to the pierce pin assembly such that upon actuation of the firing lever, the pierce pin assembly is actuated to pierce the frangible seal of a gas cartridge threaded therein, thereby allowing inflation of the article to which the inflator is heat sealed. Unfortunately, however, the inflator of U.S. Pat. No. 5,564,478 requires thick wall sections for a metal thread insert that threadably receives the gas cartridge, thereby increasing cycle times and costs during injection molding. Moreover, the escaping gas contacts the heat sealable material along with the metal components of the pierce pin assembly, which could lead to leaks to the outside if adequate sealing adhesion is not attained between such components. Moreover, the pivot pin on which the firing lever pivots is installed through a hole that must be drilled through the housing. Since the main bore core pin, during injection, has water running through it, thereby precluding the possibility of positioning a pin for the pivot hole through the core pin. It is noted that the running water through the main bore core pin is required to maintain the type of tolerances required by the O-ring that seals the bore in the assembly. Accordingly, there presently exists a need for a more easily manufacturable and assemblable heat sealable inflator that allows thinner wall sections and obviates the need for manual drilling of the hole for the pivot pin of the firing lever.
Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the inflation art.
Another object of this invention is to provide a heat-sealable inflator for inflatable articles having a housing with a mounting flange integral thereto, the housing and the flange being composed of a material that is capable of being easily sealed to the type of materials that are typically utilized in the construction of inflatable articles.
Another object of this invention is to provide a heat-sealable inflator which utilizes a minimal number of components and is therefore economical to manufacture.
Another object of this invention is to provide a heat-sealable inflator having a design which precludes deflation of the inflatable article once inflated even if the gas cartridge threaded into the housing is removed.
Another object of this invention is to provide a heat-sealable inflator having a design which eliminates a condition of non-inflation even if the firing lever thereof does not move through its full path of travel.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.